Technical Field
The present invention relates to an LED lamp bulb, especially relates to a low profile LED lamp bulb.
Description of Related Art
FIGS. 1A˜1B show a prior art.
FIG. 1A shows a prior art lead frame
FIG. 1A shows that U.S. Pat. No. 8,791,484 disclosed an LED lamp bulb which has a lead frame including a top metal 22, 22P, a metal lead 21, a branch lead 23 paralleled with the metal lead 21. A metal connection 27 connecting the metal lead 21 and the branch lead 23. An LED chip 26 straddles the gap G between the top metal pad 22P and the metal lead 21.
Since the metal lead 21 is in a shape of a longitudinal elongated rectangle and the metal connection 27 is configured near the bottom of the metal lead 21. The bottom part of the metal lead 21 is not suitable for bending inwards to make a low profile LED lamp bulb. Bending the bottom metal plate 21 inwards shall cause circuit short and damage the LED lamp bulb.
FIG. 1B shows an LED lamp bulb using the traditional lead frame of FIG. 1A
FIG. 1B shows a traditional LED lamp bulb using the lead frame of FIG. 1A. Due to the long length in longitudinal direction of the metal lead 21, an exclusive heat sink 914 in cylinder shape is needed for the lower portion of the metal lead 21 to attach. A lamp base 66 is configured on bottom of the heat sink 914. Based on the metal lead 21 to be used in the prior art LED lamp, the height of the LED lamp bulb is significantly greater than a traditional one. However, for some applications, a low profile LED lamp bulb is required while with high heat dissipation.
The prior art long metal lead 21 can not meet the height requirement for producing a low profile LED lamp bulb in some applications. Further, an exclusive heat sink 914 has to be configured for the lower portion of the metal lead 21 to attach. The prior art LED lamp bulb is bulky and heavy. The disadvantage for the prior art LED lamp bulb includes height problem and weight problem. A low profile LED lamp bulb without having an exclusive heat sink while with high heat dissipation is eagerly required.